<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        @media (min-width:320px) {
            body{
                font-size: 15px;
            }
        }
        @media (min-width:414px) {
            body{
                font-size: 18px;
            }
        }
        @media (min-width:520px) {
            body{
                font-size: 20px;
            }
        }
        @media (min-width:620px) {
            body{
                font-size: 30px;
            }
        }
    </style>
</head>

<body>
bodysssssssss
</body>

</html>